Configuring Babel

Babel is automatically configured for all .js and .jsx files via the
babel-loader with sensible defaults (e.g. with the @babel/preset-env and
@babel/preset-react if requested).

Need to extend the Babel configuration further? The easiest way is via
configureBabel():

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// webpack.config.js// ...Encore// ....configureBabel(function(babelConfig){// add additional presetsbabelConfig.presets.push('@babel/preset-flow');// no plugins are added by default, but you can add somebabelConfig.plugins.push('styled-jsx/babel');},{// node_modules is not processed through Babel by default// but you can whitelist specific modules to processincludeNodeModules:['foundation-sites'],// or completely control the exclude rule (note that you// can't use both "includeNodeModules" and "exclude" at// the same time)exclude:/bower_components/});

The @babel/preset-env preset rewrites your JavaScript so that the final syntax
will work in whatever browsers you want. To configure the browsers that you need
to support, see Adding browserslist to package.json.

After changing your "browserslist" config, you will need to manually remove the babel
cache directory:

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# On Unix run this command. On Windows, clear this directory manually$ rm -rf node_modules/.cache/babel-loader/

Instead of calling configureBabel(), you could create a .babelrc file
at the root of your project. This is a more "standard" way of configuring
Babel, but it has a downside: as soon as a .babelrc file is present,
Encore can no longer add any Babel configuration for you. For example,
if you call Encore.enableReactPreset(), the react preset will not
automatically be added to Babel: you must add it yourself in .babelrc.

As soon as a .babelrc file is present, it will take priority over the Babel
configuration added by Encore.